Background:The placenta is responsible for the nutritive, respiratory and excretory functions of the fetus. It is often overlooked in the routine evaluation of the normal gestation, receiving attention only when an abnormality is detected. Aim of the work: To determine the prevalence of sonographically thick placenta and the relation of thick placenta to fetal & maternal outcome. Patients and methods: prospective study included 25 pregnant women with thick placenta, attending to El-Hussein Obstetric outpatient clinics, as group A. 25 pregnant women with normal placental thickness were included as group B. US examination was recorded at 2nd and 3rd trimesters. After delivery, the placenta was weighted in grams.